As was said some of the greatest songs are written on a basic chord set. Theory created expansion. With theory you can take three chords to ten while retaining relative simplicity. Theory enables you to know who, where, why and what the party is all about. Then it allows you to invite all of the people that you know that weren't invited.
As I've said before it's not the B all and End all of everything but, if you have the will to learn it all, you'll understand it all.
All the best!!!!!! :cool: